package com.roadjava.tutor.util;

import org.apache.commons.lang3.StringUtils;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * @author zhaodaowen
 * @see <a href="http://www.roadjava.com">乐之者java</a>
 */
public class IpUtil {
    public static String getRealIp(HttpServletRequest request){
        String ip = request.getHeader("x-forwarded-for");
        if (StringUtils.isBlank(ip)
                || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (StringUtils.isBlank(ip)
                || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (StringUtils.isBlank(ip)
                || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (StringUtils.isBlank(ip)
                || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (StringUtils.isBlank(ip)
                || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
            if ("0:0:0:0:0:0:0:1".equals(ip) || "127.0.0.1".equals(ip)) {
                InetAddress inet = null;// 根据网卡取本机配置的IP
                try {
                    inet = InetAddress.getLocalHost();//idea-PC/192.168.212.144
                } catch (UnknownHostException e) {
                    e.printStackTrace();
                }
                ip = inet.getHostAddress();//192.168.212.144
            }
        }
        // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
        if (ip != null && ip.length() > 15) {
            if (ip.indexOf(",") > 0) {
                ip = ip.substring(0, ip.indexOf(","));
            }
        }
        return ip;
    }
}
